1. Field of the Invention
This invention relates to resilient columns of adjustable length, and particularly to improvements in a column of the type disclosed in German Utility Model No. 1,976,323.
2. The Prior Art
The known column, suitable for supporting the seat of a stool on a stool base, includes a normally upright guide tube in which a pneumatic spring of the cylinder-and-piston type is received, a valve permitting communication between the two compartments of the cylinder cavity normally sealed from each other by the piston. A compression spring is arranged between annular spring seats on the guide tube and an element of the pneumatic spring for providing resiliency when the stroke of the pneumatic spring is exhausted. The known column, while effective, is relatively expensive to assemble from elements not available at low cost.